Enzymatic pre-treatment as a means of enhancing the antibacterial activity and stability of ZnO nanoparticles sonochemically coated on cotton fabrics

Abstract

Zinc oxide nanoparticles (ZnO NP's) are known for their excellent antibacterial properties. This paper describes a method for enhancing the stability and the antibacterial activity of ZnO NPs synthesized and embedded sonochemically on cotton fabrics, by pre-treating the fabric surface with cellulase enzyme. The enzymatic pre-treatment resulted in the deposition of smaller sized NPs with improved adhesion. The reduction in particle size brought about better antibacterial performance against several types of bacteria. The sonochemically produced ZnO coating withstood 10 laundry cycles at 92 C retaining its antibacterial activity.

Simultaneous sonochemical-enzymatic coating of medical textiles with antibacterial ZnO nanoparticles

“…5a, b), showing more narrow distribution of the deposited NPs when the active enzyme was used. These observations corroborate our previous findings that the enzymatic activation of cotton surface leads to uniformly dispersed along the fibers NPs [21]. In the current study a similar effect was achieved using a single-step sono-enzymatic process.…”

“…The higher resistance of S. aureus to ZnO NPs in comparison with E. coli is due to the thicker peptidoglycan layer in the cell wall of Gram-positive bacteria, which makes them less susceptible to metal oxide NPs [33,34]. The results also showed that the durability of the antibacterial effect of the ZnO NP coating obtained in the one step sono-enzymatic coating approach against E. coli was higher compared to the already reported durability of the coating obtained in the two stepprocess (consisting of enzymatic pre-treatment of the cotton textiles followed by sonochemical deposition of ZnO NPs) [21].…”

“…Greater resistance to washings of the NPs on the samples treated with active enzyme demonstrates the significance of the enzymatic activation of the fibers surface for improved NPs adhesion and more durable treatment. The hydrolytic bio-treatment of the cotton fibers generates free hydroxyl groups on their surface, serving as anchoring points for NPs deposition [21].…”

“…In a previous work, we combined the sonochemical deposition of NPs with an enzymatic preactivation of cotton fabrics in order to create anchoring points for embedding the NPs on the textile surface, thereby improving the durability of the coating. In such way, antibacterial fabrics with durable antibacterial effect were obtained in a two-step process comprised of a cellulase pre-treatment followed by a sonochemical coating with ZnO NPs [21]. The particles were generated in situ from zinc acetate in water/ethanol alkaline solutions, and deposited on the fabrics using high intensity ultrasound.…”

Antibacterial cotton fibers treated with silver nanoparticles and quaternary ammonium salts

“…Therefore, considerable efforts have been made to make a uniform size distribution using advanced technologies. Recent studies have shown that their small sizes have more antibacterial properties than larger particles (Perelshtein et al, 2012).…”